Like this presentation? Why not share!

# ES 1.2 PPT

## by Ryan Cooper on Sep 08, 2010

• 1,422 views

### Views

Total Views
1,422
Views on SlideShare
1,061
Embed Views
361

Likes
1
68
1

### 1 Embed361

 http://mrcooperfreeport.wikispaces.com 361

### Categories

Uploaded via SlideShare as Microsoft PowerPoint

### Report content

11 of 1 previous next

• Lourdes Aquino at Lourdes Aquino ...thank's dear friend...your presentation, this and another are a great tool for teach different class. I'm Science teacher and you know that is the topics discuss in this course. 3 years ago
Are you sure you want to

## ES 1.2 PPTPresentation Transcript

• 1.2MAPPING TECHNIQUES
• The Global Grid The science and study of map making is known as cartography.  Scientists use two special measurements to describe location: ○ Latitude: the distance north or south of the equator, measured in degrees. ○ Longitude: the distance east or west of the prime meridian, measured in degrees.
• The Global Grid  Lines of latitude run E-W and measure N-S.  The line of latitude around the middle of the globe, at 0 degrees (°), is the equator.  Lines of longitude run N-S and measure E-W.  The prime meridian marks 0° of longitude.
• Map Projections A flat representation of Earth’s surface is called a map.  However, we know the Earth is round … Christopher Columbus? Maps can also be called projections since they attempt to show a three-dimensional image in two dimensions.  No map is perfect because something will always be distorted (too small, too big, out of place, etc).
• Map Projections Cylindrical Projection: A map where the Earth’s surface is projected onto a cylinder wrapped around a globe.  The equator is the viewpoint (center of the cylinder). Common example:
• Map Projections Azimuthal Projection: A map where the Earth’s surface is projected onto a flat plane at a central point.  The poles are the viewpoint (center of the plane). Common example:
• Map Projections Conic Projection: A map where the Earth’s surface is projected onto a cone surrounding a globe.  The poles are the viewpoint (center of the cone). Common example:
• Topographic Maps A topographic map is a representation of Earth’s three-dimensional surface in two dimensions showing elevation. Uses contour lines, or lines showing points of equal elevation.  Every position along a single contour line is the same elevation.
• Topographic Maps  Adjacent contour lines represent a change in elevation.  The contour interval is the difference in elevation between adjacent contour lines.  Every 5th line is called an index contour, which is a bold and labeled with elevation.
• Topographic Maps Contour lines close together represent a steeper slope while lines further apart indicate a gentler slope.
• Topographic Maps Contour lines forming a circle represent a hill or mountain.
• Topographic Maps A depression is represented by circular contour lines having hachure marks, pointing to the center of the circle.
• Topographic Maps Contour lines do not cross each other, divide, or split. Contour lines trend UP valleys and form a “V” or a “U” when they cross a stream.
• Topographic Maps A map is drawn to scale where a certain distance on the map is equal to a certain distance at the surface.The scale to the right reads1:24,000. This means 1 uniton the map is equal to 24,000units on the ground.If the 1 stands for 1 cm. onthe map, it stands for 24,000cm. on the ground. How many kilometers does the 24,000 stand for on the ground?
• Topographic MapsDIMENSIONAL ANALYSIS AGAIN! ? km. = 24,000 cm. x 1 km. 100,000 cm. Try another: The same scale reads 1:24,000. However, this time, I know the 1 stands for 1 inch. How many feet does the 24,000 stand for on actual ground? ? ft. = 24,000 in. x 1 ft. 12 in.
• Map Scale  Large Scale – show a small area (ZOOM IN). Example  1:24,000
• Map Scale  Small Scale – show a large area (ZOOM OUT). Example  1:1,000,000